Zinc is essential to cells. Intracellular zinc is tightly regulated as zinc deficiency and excess can be detrimental. Zinc transporters control movement of zinc and have a crucial role in maintaining cellular balance between apoptosis, cell growth, and disease prevention. Our preliminary findings indicate that the zinc transporter, SLC39A8, is a key regulator of zinc homeostasis in the human lung epithelium. We propose that modulation of zinc transporter expression and function during inflammatory stress is required for zinc transport into the cell and initiates cell protection against death- nducing stimuli. Our specific hypothesis is that the zinc importer SLC39A8 is the primary transporter responsible for increased zinc uptake and activation of an innate protective response against inflammatory stress in the lung epithelium. The key aims of this proposal are 1) To compare native SLC39A8-mediated zinc uptake during normal and inflammatory conditions and determine its contribution to cell survival in differentiated cultures of primary human lung epithelia and then 2) determine SLC39A8 protein structure and function with respect to cellular zinc uptake and cell survival in the BEAS2B human lung epithelial cell line via site-directed mutagenesis. We anticipate that our results will provide new insight into ARDS disease susceptibility and treatment.